| ⊦ zbrar[m + n] = mkzbranch(key, adr, r) ∧ sorted(zbrar, m, nused) ∧ n < len ∧ len ≤ nused ∧ m + nused ≤ # zbrar → scan(key, zbrar, m, len) = m + n |
zbrar[m + n] = mkzbranch(key, adr, r), n < len, sorted(zbrar, m, nused), len ≤ nused, m + nused ≤ # zbrar ⊦ scan(key, zbrar, m, len) = m + n